Will taking wellbutrin (bupropion) with lexapro help ocd and intrusive thoughts without making me gain weight?

Probably not: Wellbutrin (bupropion) will probably not make you gain weight -- but it's also unlikely to help with ocd and intrusive thoughts. Others like ssri's (like lexapro) are much better for ocd, and some are more weight-neutral (lexapro) than others. See a psychiatrist for an evaluation and discussion of options.

Unclear: Neither wellbutrin (bupropion) nor Lexapro are particularly notorious for causing weight gain. Taking wellbutrin (bupropion) with Lexapro is not a common treatment strategy for ocd. One med at a time is preferred. Behavioral therapy increases chances for success of treatment with meds.